Arthroscopy is a minimally invasive surgical technique commonly used for removing diseased or damaged tissue from intra-articular regions of the body, such as the shoulder, hip, wrist, knee, and spine. Arthroscopic shavers can be used to remove bone, cartilage, and other soft tissue from a patient's joint with less surgical trauma to the joint than conventional surgical techniques. Typically, an arthroscopic shaver is an electro-mechanical device that includes a handpiece and a cutting assembly. The cutting assembly often has an elongate, rotatable member for cutting tissue and removing tissue and fluid from a surgical site. The handpiece usually has an integrated aspiration/suction port for transferring tissue and fluid through the handpiece and to a waste collection container. The handpiece can be releasably mated to the cutting assembly so that the cutting assembly can be disposed of after each use.
During an arthroscopic procedure, the cutting assembly of the shaver is inserted into a small incision. Suction is applied to a suction port that extends through the handpiece, causing bodily tissue and associated fluids to flow through the cutting assembly and out through a proximal end of the handpiece. After the procedure is completed, the shaver blade is typically disposed of while the handpiece is sent to a processing center for cleaning and sterilization. Because fluid and tissue can become lodged inside of the handpiece, the handpiece must be thoroughly cleaned after each use through an aggressive series of brushing operations and/or using automated washing machines. Although the brushing is necessary to remove biological material from the handpiece, it can decrease the durability of the mechanical components and damage the seals within the shaver handpiece. There is also evidence that these conventional cleaning techniques are ineffective at removing biological material. The United States Food and Drug Administration has investigated the cleaning of shaver handpieces and found numerous cases where tissue has remained in the shavers after cleaning, compromising the sterility of a surgical site.
A further problem with current tissue shavers is that during an arthroscopic procedure they have a tendency to generate a substantial amount of heat. This is because the amount of power used to operate the shaver can be significant. For example, a motor inside of a handpiece of a shaver can require 50 or more watts of power to operate. When a shaver generates a substantial amount of heat, it can be difficult or otherwise uncomfortable for the user to hold the shaver handpiece in his or her hand. Furthermore, the performance of the shaver can be negatively impacted due to overheating.
Accordingly, there remains a need for a tissue shaver that is easier to clean, has a decreased risk of contaminating a surgical site, and that reduces or otherwise counteracts the amount of heat generated by the device.